This invention relates to fuel injectors and in particular to extremely high pressure periodic injectors where fuel is injected in discreet pulses at pressures sufficient to cause gasification upon injection. This invention relates to our application Ser. No. 885,304, filed 18 Apr. 1992, entitled, FUEL INJECTOR SYSTEM.
In many applications, the efficiency of an engine increases as the operating pressures increase. In reciprocal engines, it is desirable that the injection pressure exceed the volumetric pressure of the combustion chamber by a factor of ten. The use of confined volume precombustion chambers and the design of hyper-pressure engines requires that in some instances, the injection pressure be boosted to one hundred to two hundred thousand psi. At these pressures, structural components of the injector system become large and cumbersome with the potential of leaks and rupture an unavoidable consideration.
The injector systems of this invention are designed to enable ultra high pressure injections to be achieved without substantial modification in the fuel delivery system. Ultra high pressures are localized in sections of the injector unit. In this manner, the fuel supply lines, common rail, and injector feed lines can be maintained at conventional injection pressures with the exceedingly high pressure of injection isolated in an injector component and in portions of a booster component. In addition to substantial savings in the cost of components, the isolation of hyper-pressure fluids primarily in the injector allows for greater precision in the start and stop of the injection cycle.